Beer Festival Calibration

Here at Purr Towers we all like beer and we all like small accurate internet connected temperature sensors. So we thought why don’t we bring the two together? This weeks 43rd Cambridge Beer Festival seemed like the perfect opportunity, so as the latest in a long line of Cambridge technological firsts Purrmetrix are pleased to bring you the first internet of things enabled beer festival. Welcome to the future.

What’s Purr?

Purrmetrix build small retrofit-able wireless battery temperature sensors that report their temperature every 17 seconds or so via a 433MHz radio through a gateway and then onto our database. We also provide software that allows our customers to browse, graph and consume their data and run various kinds of analytics and to set alerts. So we had a chat with the organisers of the beer festival to ask them what might be useful and we quickly settled on a plan.

Deploying kittens to keep watch over the beer

We call our temperature sensors kittens. We deployed 26 kittens in total. 11 kittens are measuring the ambient temperature in the main marquee. These are spread around the front of the various bars. If you look carefully on the posts at just above head height you might catch site of our smiley faced kittens blinking away, they flash every time they report there temperature.

A bundle of temperature monitoring kittens

A bundle of kittens ready to go and monitor beer temperature

We also placed 9 kittens in the ‘Igloo’ which is a chilled cellar like room where the Key Keg beer and some of the other craft beers are stored. And we also chose 6 beers where we placed two kittens on the back of each cask. Disclaimer: the kittens on the beer are measuring the ambient temperature of the air around them, which will be a little warmer than the temperature of the beer. But the beer is actively cooled, by chilled water pumped over the casks and the casks and the kittens are well insulated. The fact that the temperature these kittens are reporting is very stable tells me the system is in a nice steady state so using this data as a proxy for the beer temperature is not a totally stupid thing to do. But can we do better?

Tim’s grim experiment

Of course we can. When I go to the festival this evening I will be taking a modified kitten that has been sheathed in a prophylactic, which I will be using to measure the temperature of these beers as they will be served to the punters. This will allow us to added a small correction to calibrate our kittens.  I need to make clear it will only be my beer the device will be dipped in*  I will report back on how this goes tomorrow. Anyway pop to the earlier blogpost  https://www.purrmetrix.com/beer-festivals-too-hot-to-handle/ to get the low down to look at the data that we are collecting and feel free to email us or tweet if you want to know more.

*That’s a relief. Ed.

Cambridge Beer Festivals – all the beers…

If you want to know more about the condition of our sample beers at the Cambridge Beer Festival, we have all the data you could want. So what’s the story?

Firstly, you might want to know what the ambient temperatures are in the tent:

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And how that relates to all the beers:

Screen Shot 2016-06-06 at 16.11.40

Good to see a signficant difference between ambient and the beers!

We’ll put the views for each beer into separate posts, for technical reasons your author doesn’t entirely understand, but relate to inadvertent triggering of The End of Times, apparently.

Beer Festivals: too hot to handle?

Here at Purrmetrix we’ve been getting very interested in beer recently. And not just for the obvious reasons.

Fact is, beer, especially real ale, is a living thing, and sensitive to temperature. Good pubs put effort into making sure their cellars maintain the 11-13°c that is the optimum for keeping cask ales at their best. Organisations like CAMRA and Cask Marque offer training and accreditation, with an annual survey of pubs testing for temperature, taste and aroma.

Is British beer too warm?

Despite this, the old legend that British beer is served warm refuses to die, and in fact might be grounded in some truth. One of the earliest Cask Marque surveys reported more than 2000 pubs serving beer warmer that 13°, with a number consistently producing pints in excess of 20° and in one case even 35°C. Yuck.

Beer this warm not only spoils more quickly but also tends to ‘fob’ or froth, meaning a lot more is wasted. The British Beer and Pub Association estimates that for a 10 tap bar warm cellars can reduce yield and waste up to £14,000 of revenue each year. We’re guessing no landlord wants this to happen and warm beer is more often the result of a hidden problem – hotspots in the cellar, or brewlines run past a fridge outlet. Which is why we’re getting very interested, because one thing we love at Purrmetrix is finding hidden problems, bringing them out into the light, and giving them a good kicking.

Delivering quality at Beer Festivals

Meanwhile, whatever the difficulties in guaranteeing a decent pint in a pub, a different challenge faces the organisers of beer festivals. Beer festivals are enjoying a rennaissance, clocking up audiences of thousands. Imagine the problems a landlord for a large town centre pub with 8 ales on tap faces. Now multiply that by 10, and add in much more limited ability to control the climate and a clientele that really, really cares about quality. Once the sun comes out and your marquee warms up, how are you going to deliver?

Next week we’re going to have a look at this question at the Cambridge Beer Festival, one of the oldest and largest beer festivals in the UK. 200 beers, 60 ciders and Perries. Foreign beers, English wine and even Mead. And also: 50 kittens, sitting on the more popular casks and monitoring their temperature. We’re hoping to break some new ground here – we are measuring the surface temperature of the casks, not their contents, with the aim of gathering enough data to determine the relationship between the two. Other things that interest us: can we alert you, the Beer Festival customer, to ‘low beer’ status on each cask and let you get that critical last pint before it runs out?

So if you’re planning on going to the Beer Festival and want to do a bit of public science, check our data here for a sample of stock and see if you can determine the point at which the beer is getting low. There’s a live feed across the whole site and you can follow us on Twitter for more updates.